Diseases are complex and their causes myriad. A relatively new field of research known as the “social determinants of health” shows that merely treating illness is not the best approach to what ails us, we need a comprehensive overhaul of what we are doing and to address underlying social mechanisms that harm well-being.

My medical training in the 1970s focused on the diagnosis and treatment of diseases – it rarely addressed the question of why people got them.

But as a young doctor working in child health, particularly with Aboriginal children, it became obvious to me that prevention of disease was by far the best way to practice medicine; it’s more humane and definitely more cost-effective.

In 1972, I left Australia to study epidemiology and public health in the United Kingdom and then the United States, where these disciplines were well advanced. I learnt of the limitations of modern medicine, that prevention was the key to health and that many diseases commenced in social adversity.

The most exciting thing for me was that it was also the beginning of the push for disease registers, large population data sets and data linkage - all skills I brought back to Australia.

Wide open road

Coming back to Australia in 1977, I was excited to be returning to a virtual “desert” waiting to be populated with databases of evidence to help start successful preventative activities here.

Australia has led the world in road accident prevention, tobacco control, vaccination coverage, and in HIV/AIDS. All these efforts needed population-level data to obtain accurate prevalence rates and determine risk and protective factors. This evidence was then applied to create environments for prevention.

My particular interest in child health has resulted in the mandatory fortification of flour with folate to prevent spina bifida. And in establishing some of the best population databases internationally to monitor, research and evaluate a range of child and adolescent problems in health, education, child protection, disabilities and juvenile justice.

These major public health successes are hugely cost-effective because they help us prevent diseases for which costs are spiralling. But even bigger gains can (and must) be made by addressing the social determinants of health across the whole of society.

It’s becoming more common to hear people talk about the social determinants of health, so let me explain what they’re all about.

Social determinants

Within populations, even in wealthy ones such as Australia, analyses of almost all diseases, as well as educational outcomes, disabilities, mental illness, substance abuse, child abuse and neglect and criminal behaviour show a strong relationship with socioeconomic measures.

That means there’s a gradient across society with more problems occurring as you move from the better off to those worse off (in terms of resources).

There are also interesting international comparisons between countries that show a strong relationship between measures of health (such as infant mortality, or life expectancy) and the socioeconomic parameters, such as gross domestic product (GDP).

Despite being one of the poorest countries in the world, Cuba has better life expectancy and infant mortality than the United States.Patrick Nouhailler

On the whole, the pattern is the same – greater economic prosperity leads to lower disease rates. But, interestingly, above a certain level of wealth, the rates flatten out.

And there are some paradoxical countries whose patterns are opposite to the overall trends. Cuba, for example, is one of the poorest countries in the world but has better life expectancy and infant mortality than its neighbour, the United States, which also happens to be the world’s wealthiest country!

Literacy and numeracy rates in Cuba are close to 100% and the country’s free health and education systems focus on prevention and enhancing positive outcomes rather than waiting for disease and then treating it (as happens in United States and, increasingly, in Australia).

Saudi Arabia, one of the world’s richest countries, has very high infant mortality and low life expectancy. Literacy rates there, particularly among women, are very low. Cuba is poor but socially egalitarian while Saudi Arabia is wealthy but socially divided.

But why are diseases and almost all of our societal problems so strongly influenced by social factors and what can we do about it?

Following Mexico’s example

When we study the paths into these problems in health and well-being, we find that many people start in a position of disadvantage, with poor living conditions, low levels of education, and unhealthy lifestyles. Early intervention is crucial if we are to influence the causes of irreversible conditions.

Inequalities are bad for everyone’s health. We need to invest in social, environmental, and community infrastructure for health. And we need to ensure the budget is more evenly distributed (as is done in both Sweden by proportional taxing and Japan by having more equality in salary levels).

In the early 2000s, the Mexican health minister developed a social determinants of health model. Each government department (education, transport, water, housing, finance, infrastructure, as well as health) had to prepare a plan for better health.

The result was a superb blueprint for a society totally committed to prevention. Mexico still has problems of poverty but has leapt ahead in terms of health and development.

The new government in Australia could use this kind of blueprint for the nation’s future health and well-being – we need to convince them that this is a crucial investment.